MBD Simulation of IC Engine Valve Train

Design Model of IC Engine Valve Train :

Cam :

Push Rod:

Rocker Arm:

Valve:

Valve Mount:

Assembly Model of IC Engine Valve Train:

Simulation:

Simulation is done for following two cases:

Sl.No	CAM Lift (mm)	Speed (RPM)	Material
1	3.5	1500	Cast Carbon Steel
2	6	1500	Cast Carbon Steel

During the motion analysis contacts between Cam and push rod, push rod and rocker arm, rocker arm and valve are established and given the rotation to the cam with 1500 RPM.

Linear spring between a valve and the valve mount with the spring stiffness of 10 N/mm and free length 45 mm i.e with initial tension is established.

For the two cases plots are plotted for

• Valve Lift.
• The contact force between
  • Cam and Push Rod
  • Pushrod and Rocker Arm
  • Rocker Arm and Valve

For Case 1:

Cam Design :

Valve Lift:

Contact Force Between

a) Cam and Push Rod

b) Push Rod and Rocker Arm

c) Rocker Arm and Valve

For Case 2:

Cam Design:

Valve Lift :

Contact Force Between

a) Cam And Push Rod

b) Push Rod and Rocker Arm

c) Rocker arm and Valve

The contact force between the Rocker arm and valve varies while measuring with respect to the X direction and measuring with respect to magnitude. Because the magnitude represents net contact force between the parts, while the contact force along the X direction is the force only in that direction of the bodies.

From Plots:

Valve Lift of the IC Engine Valve Train increses as the increases of the cam lift. For the above two cases the valve lift is increased from 3.5mm cam lift to 6 mm cam lift.

Contact Force between contact bodies also increases as the cam lift is increases.